Grating-free high-x InP/InxGa1-xAs mid-wavelength infrared QWIP focal plane array

Beşikci C., Balcı S. V., Tanış O., Güngör O. O., Arpaguş E.

OPTO-ELECTRONICS REVIEW, vol.31, no.special issue, pp.1-4, 2023 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 31 Issue: special issue
  • Publication Date: 2023
  • Doi Number: 10.24425/opelre.2023.144563
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Central & Eastern European Academic Source (CEEAS), Compendex
  • Page Numbers: pp.1-4
  • Middle East Technical University Affiliated: Yes


The authors report the characteristics of a diffraction-grating-free mid-wavelength infrared InP/In0.85Ga0.15As quantum well infrared photodetector focal plane array with a 640 x 512 format and a 15 .m pitch. Combination of a normal incident radiation sensing ability of the high-x InxGa1-xAs quantum wells with a large gain property of the InP barriers led to a diffraction-grating-free quantum well infrared photodetector focal plane array with characteristics displaying great promise to keep the status of the quantum well infrared photodetector as a robust member of the new generation thermal imaging sensor family. The focal plane array exhibited excellent uniformity with noise equivalent temperature difference nonuniformity as low as 10% and a mean noise equivalent temperature difference below 20 mK with f/2 optics at 78 K in the absence of grating. Elimination of the diffraction-grating and large enough conversion efficiency (as high as -70% at a -3.5 V bias voltage) abolish the bottlenecks of the quantum well infrared photodetector technology for the new generation very small-pitch focal plane arrays.